1. Field of the Invention
The present invention relates to a door closer apparatus configured to retract a door to a full lock state when the door is closed to a half lock state.
2. Description of the Related Art
A locking apparatus provided on a hinge-type door at an entrance of an automotive vehicle has two locking functions including a full lock function for prohibiting the door from opening in a state in which the door is completely closed, and a half lock function for prohibiting the door from opening in a half-shut state.
Using FIG. 10 to FIG. 12, an example of a locking apparatus as described above will be described. FIG. 10 is a configuration drawing showing an unlocked state of the locking apparatus, FIG. 11 is a configuration drawing showing a half lock state of the locking apparatus shown in FIG. 10, and FIG. 12 is a configuration drawing showing a full lock state of the locking apparatus in FIG. 10.
In FIG. 10, a striker 1 is provided on one of the door and a body. Provided on the other one of the door and the body so as to be rotatable is a latch 5 formed with a groove 3 which allows entry of the striker 1.
The latch 5 is urged in an unlocking direction (the direction indicated by an arrow A in the drawing) which allows the striker 1 to enter the groove 3 by an urging portion, not shown.
A pole 7 is rotatably provided at a position adjacent to the latch 5. The pole 7 is urged in a direction coming into abutment with the latch 5 (the direction indicated by an arrow B in the drawing) by an urging portion, not shown.
Subsequently, when the door is closed, the striker 1 presses a wall surface of the groove 3 of the latch 5, and the latch 5 rotates in a direction opposite from the direction of the arrow A against an urging force of the urging portion. Then, an engaging portion 7a of the pole 7 and a half lock engaging portion 3a of the wall surface of the groove 3 of the latch 5 engage and a half-locked (half-shut) state which prohibits the door from opening in the half-shut state is achieved as shown in FIG. 11.
When the door is further closed, the striker 1 presses the wall surface of the groove 3 of the latch 5, and the latch 5 further rotates in the direction opposite from the direction of the arrow A against the urging force of the urging portion. Then, the engaging portion 7a of the pole 7 and a full lock engaging portion 5a of the latch 5 engage and a full lock state which prohibits the door from opening in the state in which the door is completely closed is achieved as shown in FIG. 12.
On the other hand, the door in this configuration may be provided with a door closer apparatus configured to retract the door to the full lock state when the door is closed to a position in the vicinity of the half lock state (half-shut). The retraction of the door of the door closer apparatus is normally performed by driving the latch 5 to rotate.
In the door closer apparatus as described above, detection of the half lock state and the full lock state is performed by using a rotary switch provided on an axis of rotation of the latch 5 for detecting a rotational angle of the latch 5 (see JP-A-2006-144367).
Normally, in the door closer apparatus, a timing to start the retraction of the door is determined by detecting the rotational angle of the latch 5. Having errors to an extent in the timing to start the retraction of the door presents no significant problem.
In contrast, a timing to stop the retraction of the door is immediately after having become the full lock state in order to ensure the locking of the door. Therefore, it is necessary to detect the fact that the door is in the full lock state.
As a method of detecting the full locked state, detecting the pole 7 which engages the latch 5 in the full lock state and rotates significantly is conceivable. However, since the pole 7 engages the latch 5 and rotates significantly even in the half lock state, the full locking cannot be detected only by the movement of the pole 7.
Therefore, the following methods are proposed as methods of detecting the full locking.
(1) A method of detecting the rotation of the latch by the rotary switch.
(2) A method of detecting the rotation of the latch by the rotary switch and detecting also the rotation of the pole.
The method (1) detects the full locking only on the basis of the rotational angle of the latch, the full locking cannot be detected accurately due to the error. The method (2) is capable of detecting the full locking accurately by using a hook and the pole.
Both of the methods (1) and (2) employ the rotary switch for detecting two rotational angles (half locking and full locking) of the latch. The rotary switch is large in size and hence requires a large space for the installation thereof. Since the rotary switch is provided on an axis of rotation of the pole 7, there is a problem in that layout of the locking apparatus is constrained. In addition, the rotary switch is a specific component, and has a problem of being expensive.